The present disclosure relates to an electrophotographic type of image forming apparatus.
An image forming apparatus of an electrophotographic type, such as a copying machine or a facsimile device includes a developing apparatus which supplies toner to a photosensitive drum, which is an image bearing member, and a toner container which accommodates toner to be supplied to the developing apparatus. The developing apparatus has a developing roller onto which toner to be supplied to the photosensitive drum is deposited by static electricity, and a screw which circulates the toner to the developing roller while agitating the toner. The toner container has an accommodating section for accommodating toner, and conveyance means for conveying toner from the accommodating section to the developing apparatus. The developing apparatus is replenished with toner from the toner container by aligning and assembling a toner replenishment port situated on a developing apparatus side, with a toner discharge port on a toner container side.
There is a conventional developing apparatus in which a restricting section for locally restricting the toner conveyance capacity is provided in the screw, in order to adjust the toner replenishment volume. In the case of this developing apparatus, a region of toner retention caused by the restricting section may reach to the toner replenishment port. If toner is replenished from a toner replenishment port in this state, then the retained toner is pushed and compacted and a toner wall, which is an agglomeration of toner, is liable to form along the periphery of the screw. When the toner replenishment port is blocked off by the toner wall thus formed, then the toner is not supplied normally to the developing apparatus and the toner volume inside the developing apparatus declines. Therefore, thinning occurs in the image, giving rise to decline in the printing quality.
The object of the present disclosure is to provide an image forming apparatus which prevents formation of a toner wall in the toner replenishment port and achieves stabilization of toner replenishment.